Trace shielding for input devices

ABSTRACT

Embodiments of the present invention generally provide shield electrodes for shielding one or more conductive routing traces from one or more receiver electrodes in an input device comprising a display device integrated with a sensing device to reduce the capacitive coupling between the conductive routing traces and the receiver electrodes. The shield electrode may be configured to reduce the effect of an input object on the capacitive coupling between the conductive routing traces and the receiver electrodes. In other embodiments, end portions of common electrodes shield the receiver electrodes from the conductive routing traces, thereby reducing the capacitive coupling between the receiver electrodes and the conductive routing traces.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. Provisional Patent ApplicationSer. No. 61/507,369, filed Jul. 13, 2011, which is herein incorporatedby reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present invention generally relate to a system anddevice for improving the interference performance of an input deviceintegrated with a display device.

2. Description of the Related Art

Input devices including proximity sensor devices (also commonly calledtouchpads or touch sensor devices) are widely used in a variety ofelectronic systems. A proximity sensor device typically includes asensing region, often demarked by a surface, in which the proximitysensor device determines the presence, location, and/or motion of one ormore input objects. Proximity sensor devices may be used to provideinterfaces for the electronic system. For example, proximity sensordevices are often used as input devices for larger computing systems(such as opaque touchpads integrated in, or peripheral to, notebook ordesktop computers). Proximity sensor devices are also often used insmaller computing systems (such as touch screens integrated in cellularphones).

In some configurations, the proximity sensor devices are integrated withsupporting components, such as display devices, to provide a desiredcombined function or to provide a desirable complete device package. Insuch configurations, the integrated device may include a plurality ofcommon transmitter electrodes configured for display updating and fortransmitting input sensing signals, and a plurality of receiverelectrodes for receiving the results of the input sensing signals.

As the computing displays in which these capacitive sensing devices areintegrated (e.g., touch screen displays) increase in size andresolution, the number of transmitter and receiver electrodes is alsoincreased. As a result, a greater number of routing traces is requiredto connect the electrodes to the modules by which they are operated. Inaddition, as device thickness decreases, the distance between therouting traces, through which signals are transmitted to the commontransmitter electrodes, and the sensing components, such as the receiverelectrodes, is decreased, resulting in undesired interference betweenthe routing traces and the sensing components, especially when an inputobject approaches the sensing region of the input device.

Therefore, there is a need for an improved system and device forreducing interference in a display device with an integrated inputdevice.

SUMMARY OF THE INVENTION

Embodiments of the present invention generally provide shield electrodesfor shielding one or more conductive routing traces from one or morereceiver electrodes in an input device integrated with a display deviceto reduce the capacitive coupling between the conductive routing tracesand the receiver electrodes. The shield electrode may be configured toreduce the effect of an input object on the capacitive coupling betweenthe conductive routing traces and the receiver electrodes. In otherembodiments, end portions of common electrodes shield the receiverelectrodes from the conductive routing traces, thereby reducing thecapacitive coupling between the receiver electrodes and the conductiverouting traces.

Embodiments of the present invention may also provide a touch screendevice with an integrated capacitive sensing device. The touch screendevice includes a display device and a plurality of common electrodesdisposed in the display device. The plurality of common electrodes isconfigured for updating the display device and for transmittingtransmitter signals for capacitive sensing. The touch screen devicefurther includes a plurality of receiver electrodes and a plurality ofconductive routing traces coupled to the plurality of common electrodes.The conductive routing traces are shielded from the plurality ofreceiver electrodes in a manner that reduces a capacitive couplingbetween the conductive routing traces and the receiver electrodes and/orat least partially reduces the effect of input objects on the couplingbetween the conductive routing traces and the receiver electrodes.

Embodiments of the present invention may also provide a touch screendevice with an integrated capacitive sensing device. The touch screendevice includes a display device and a plurality of common electrodesdisposed in the display device. The plurality of common electrodes isconfigured for updating the display device and for transmittingtransmitter signals for capacitive sensing. The touch screen devicefurther includes a plurality of receiver electrodes and a plurality ofconductive routing traces coupled to the plurality of common electrodes.The conductive routing traces are shielded from the plurality ofreceiver electrodes in a manner that reduces a capacitive couplingbetween the conductive routing traces and the receiver electrodes. Thetouch screen device further includes a shield electrode positioned toshield the plurality of conductive routing traces from the plurality ofreceiver electrodes. The shield electrode is configured to reduce theeffect of an input object on the capacitive coupling between theconductive routing traces and the receiver electrodes.

Embodiments of the present invention may also provide a touch screendevice with an integrated capacitive sensing device. The touch screendevice includes a display device and a plurality of common electrodesdisposed in the display device. The plurality of common electrodes isconfigured for updating the display device and for transmittingtransmitter signals for capacitive sensing. The touch screen devicefurther includes a plurality of receiver electrodes and a plurality ofconductive routing traces coupled to the plurality of common electrodes.The conductive routing traces are shielded from the plurality ofreceiver electrodes in a manner that reduces a capacitive couplingbetween the conductive routing traces and the receiver electrodes. Thereceiver electrodes are shielded from the plurality of conductiverouting traces by end portions of the plurality of common electrodes.The common electrodes are configured to reduce the effect of an inputobject on the capacitive coupling between the conductive routing tracesand the receiver electrodes. The end portions of the plurality of commonelectrodes may be disposed between the plurality of receiver electrodesand the plurality of conductive routing traces. Each end portion of thecommon electrodes may be coupled to a respective one of the plurality ofconductive routing traces through a via.

Embodiments of the present invention may also provide a system forcapacitive sensing in a display device. The system includes a pluralityof common electrodes configured for display updating and for capacitivesensing and a plurality of conductive routing traces coupled to theplurality of common electrodes. The system further includes a drivermodule coupled to the plurality of conductive routing traces andconfigured to drive transmitter signals onto the plurality of commonelectrodes. The system further includes a plurality of receiverelectrodes shielded from the plurality of conductive routing traces in amanner that reduces influence of a presence of an input object oncapacitive coupling between the plurality of receiver electrodes andconductive routing traces. The system further includes a receiver modulecoupled to the plurality of receiver electrodes and configured toreceive resulting signals with the receiver electrodes. The system mayfurther comprise a shield electrode positioned to shield the pluralityof conductive routing traces from the plurality of receiver electrodes.In one embodiment, the receiver module is disposed on the sealing glassor coupled to the sealing glass though a flexible connector (e.g., aflexible printed circuit board) and a conductive film. In variousembodiments, the flexible connector may also comprise a shieldelectrode. In one such embodiment, the flexible connector may comprise ashield electrode distinct from the shield electrode positioned to shieldthe plurality of conductive routing traces from the plurality ofreceiver electrodes.

Embodiments of the present invention may also provide a system forcapacitive sensing in a display device. The system includes a pluralityof common electrodes configured for display updating and for capacitivesensing and a plurality of conductive routing traces coupled to theplurality of common electrodes. The system further includes a drivermodule coupled to the plurality of conductive routing traces andconfigured to drive transmitter signals onto the plurality of commonelectrodes. The system further includes a plurality of receiverelectrodes shielded from the plurality of conductive routing traces in amanner that reduces influence of a presence of an input object oncapacitive coupling between the plurality of receiver electrodes andconductive routing traces. The system further includes a receiver modulecoupled to the plurality of receiver electrodes and configured toreceive resulting signals with the receiver electrodes. The receiverelectrodes are shielded from the plurality of conductive routing tracesby end portions of the plurality of common electrodes. The end portionsof the common electrodes may be positioned between the plurality ofreceiver electrodes and the plurality of conductive routing traces. Eachend portion of the plurality of common electrodes may be coupled to arespective one of the plurality of conductive routing traces through avia.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features can be understoodin detail, a more particular description, briefly summarized above, maybe had by reference to embodiments, some of which are illustrated in theappended drawings. It is to be noted, however, that the appendeddrawings illustrate only embodiments of the invention and are thereforenot to be considered limiting of its scope, for the invention may admitto other equally effective embodiments.

FIG. 1 is a display device having an integrated input device.

FIG. 2 is a partial schematic plan view of the input device of FIG. 1 inaccordance with embodiments of the invention.

FIG. 3 is a partial schematic plan view of the input device having atwo-shield configuration.

FIG. 4 is a partial schematic plan view of the input device having asingle-shield configuration.

FIG. 5 is an exploded schematic view of a liquid crystal display (LCD)device integrated with input device.

FIG. 6 is an exploded schematic view of a LCD device integrated withinput device.

FIG. 7 is an exploded schematic view of a LCD device illustratinglocations at which one or more shield electrode(s) may be disposed.

FIG. 8 is an exploded schematic view of an organic light-emitting diode(OLED) display device with input device.

FIG. 9 is an exploded schematic view of an OLED display deviceillustrating locations at which one or more shield electrode(s) may bedisposed.

FIG. 10 is a schematic plan view in which receiver electrodes areshielded from conductive routing traces by end portions of commonelectrodes.

FIGS. 11A and 11B are schematic cross-sectional views of the input anddisplay device of FIG. 10 in accordance with different embodiments ofthe invention.

FIG. 12 is a schematic plan view of the input and display device of FIG.10 in which apertures are formed in common electrodes to decreasecoupling between conductive routing traces and common electrodes.

FIGS. 13A and 13B are schematic cross-sectional views of the input anddisplay device of FIG. 12 in accordance with different embodiments ofthe invention.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements disclosed in oneembodiment may be beneficially utilized on other embodiments withoutspecific recitation.

DETAILED DESCRIPTION

The following detailed description is merely exemplary in nature and isnot intended to limit the invention or the application and uses of theinvention. Furthermore, there is no intention to be bound by anyexpressed or implied theory presented in the preceding technical field,background, brief summary or the following detailed description.

Various embodiments of the present invention generally provide shieldelectrodes for shielding one or more conductive routing traces from oneor more receiver electrodes in an input device comprising a displaydevice integrated with a sensing device to reduce the capacitivecoupling between the conductive routing traces and the receiverelectrodes. The shield electrode may be configured to reduce the effectof an input object on the capacitive coupling between the conductiverouting traces and the receiver electrodes. In other embodiments, endportions of common electrodes shield the receiver electrodes from theconductive routing traces, thereby reducing the capacitive couplingbetween the receiver electrodes and the conductive routing traces.

Turning now to the figures, FIG. 1 is a block diagram of an exemplaryinput device 100 in accordance with embodiments of the invention. Theinput device 100 comprises a display device 160 integrated with asensing device, such as a capacitive sensing device. The input device100 may be configured to provide input to an electronic system (notshown). As used in this document, the term “electronic system” (or“electronic device”) broadly refers to any system capable ofelectronically processing information. Some non-limiting examples ofelectronic systems include personal computers of all sizes and shapes,such as desktop computers, laptop computers, netbook computers, tablets,web browsers, e-book readers, and personal digital assistants (PDAs).Additional example electronic systems include composite input devices,such as physical keyboards that include input device 100 and separatejoysticks or key switches. Further example electronic systems includeperipherals such as data input devices (including remote controls andmice) and data output devices (including display screens and printers).Other examples include remote terminals, kiosks, and video game machines(e.g., video game consoles, portable gaming devices, and the like).Other examples include communication devices (including cellular phones,such as smart phones), and media devices (including recorders, editors,and players such as televisions, set-top boxes, music players, digitalphoto frames, and digital cameras). Additionally, the electronic systemcould be a host or a slave to the input device.

The input device 100 can be implemented as a physical part of theelectronic system or can be physically separate from the electronicsystem. As appropriate, the input device 100 may communicate with partsof the electronic system using any one or more of the following: buses,networks, and other wired or wireless interconnections (including serialand or parallel connections). Examples include I²C, SPI, PS/2, UniversalSerial Bus (USB), Bluetooth, RF, and IRDA.

In the embodiment depicted in FIG. 1, the input device 100 is shown asaproximity sensor device (also often referred to as a “touchpad” or a“touch sensor device”) configured to sense input provided by one or moreinput objects 140 in a sensing region 120. Example input objects includefingers and styli, as shown in FIG. 1.

Sensing region 120 overlays the display screen of the display device 160and encompasses any space above, around, in, and/or near the inputdevice 100 in which the input device 100 is able to detect user input(e.g., user input provided by one or more input objects 140). The sizes,shapes, and locations of particular sensing regions may vary widely fromembodiment to embodiment. In some embodiments, the sensing region 120extends from a surface of the input device 100 in one or more directionsinto space until signal-to-noise ratios prevent sufficiently accurateobject detection. The distance to which this sensing region 120 extendsin a particular direction, in various embodiments, may be on the orderof less than a millimeter, millimeters, centimeters, or more, and mayvary significantly with the type of sensing technology used and theaccuracy desired. Thus, some embodiments sense input that comprises nocontact with any surfaces of the input device 100, contact with an inputsurface (e.g., a touch surface) of the input device 100, contact with aninput surface of the input device 100 coupled with some amount ofapplied force or pressure, and/or a combination thereof. In variousembodiments, input surfaces may be provided by surfaces of casingswithin which the sensor electrodes reside, by face sheets applied overthe sensor electrodes or any casings, etc. In some embodiments, thesensing region 120 has a rectangular shape when projected onto an inputsurface of the input device 100. The facesheet (e.g., LCD Lens 510) mayprovide a useful contact surface for an input object.

The input device 100 may utilize any combination of sensor componentsand sensing technologies to detect user input in the sensing region 120.The input device 100 comprises one or more sensing elements fordetecting user input. Some implementations are configured to provideimages that span one, two, three, or higher dimensional spaces. Someimplementations are configured to provide projections of input alongparticular axes or planes. Cursors, menus, lists, and items may bedisplayed as part of a graphical user interface and may be scaled,positioned, selected scrolled, or moved based at least partially basedon positional information due to an input object in sensing region 120.

In some capacitive implementations of the input device 100, voltage orcurrent is applied to create an electric field. Nearby input objectscause changes in the electric field and produce detectable changes incapacitive coupling that may be detected as changes in voltage, current,or the like.

Some capacitive implementations utilize arrays or other regular orirregular patterns of capacitive sensing elements 150, such as sensorelectrodes, to create electric fields. In some capacitiveimplementations, separate sensing elements 150 may be ohmically shortedtogether to form larger sensor electrodes. Some capacitiveimplementations utilize resistive sheets (e.g., may comprise a resistivematerial such as ITO or the like), which may be uniformly resistive. Invarious embodiments, some capacitive implementations utilize resistivesheets which may be comprised of a material comprising open meshes(about less than ten percent filled, but depending on application, thepercentage may be higher or lower) of highly conductive materials (e.g.,metals).

Some capacitive implementations utilize “self capacitance” (or “absolutecapacitance”) sensing methods based on changes in the capacitivecoupling between sensor electrodes and an input object. In variousembodiments, an input object near the sensor electrodes alters theelectric field near the sensor electrodes, changing the measuredcapacitive coupling. In one implementation, an absolute capacitancesensing method operates by modulating sensor electrodes with respect toa reference voltage (e.g., system ground) and by detecting thecapacitive coupling between the sensor electrodes and input objects.

Some capacitive implementations utilize “mutual capacitance” (or“transcapacitance”) sensing methods based on changes in the capacitivecoupling between sensor electrodes. In various embodiments, an inputobject near the sensor electrodes alters the electric field between thesensor electrodes, changing the measured capacitive coupling. In oneimplementation, a transcapacitive sensing method operates by detectingthe capacitive coupling between one or more transmitter sensorelectrodes (also “transmitter electrodes” or “transmitters”) and one ormore receiver sensor electrodes (also “receiver electrodes” or“receivers”). Transmitter sensor electrodes may be modulated relative toa reference voltage (e.g., system ground) to transmit transmittersignals. Receiver sensor electrodes may be held substantially constantrelative to the reference voltage to facilitate receipt of resultingsignals. A resulting signal may comprise effect(s) corresponding to oneor more transmitter signals and/or to one or more sources ofenvironmental interference (e.g., other electromagnetic signals). Sensorelectrodes may be dedicated transmitters or receivers, or sensorelectrodes may be configured to both transmit and receive.Alternatively, the receiver electrodes may be modulated relative toground.

In FIG. 1, a processing system 110 is shown as part of the input device100. The processing system 110 is configured to operate the hardware ofthe input device 100 to detect input in the sensing region 120. Thesensing region 120 includes an array of sensing elements 150. Theprocessing system 110 comprises parts of, or all of, one or moreintegrated circuits (ICs) and/or other circuitry components. Forexample, a processing system for a mutual capacitance sensor device maycomprise transmitter circuitry configured to transmit signals withtransmitter sensor electrodes and/or receiver circuitry configured toreceive signals with receiver sensor electrodes. In some embodiments,the processing system 110 also comprises electronically-readableinstructions, such as firmware code, software code, and/or the like. Insome embodiments, components of the processing system 110 are locatedtogether, such as near sensing element(s) of the input device 100. Inother embodiments, components of processing system 110 are physicallyseparate with one or more components close to sensing element(s) ofinput device 100 and one or more components elsewhere. For example, theinput device 100 may be a peripheral coupled to a desktop computer, andthe processing system 110 may include software configured to run on acentral processing unit of the desktop computer and one or more ICs(perhaps with associated firmware) separate from the central processingunit. As another example, the input device 100 may be physicallyintegrated in a phone, and the processing system 110 may comprisecircuits and firmware that are part of a main processor of the phone. Insome embodiments, the processing system 110 is dedicated to implementingthe input device 100. In other embodiments, the processing system 110also performs other functions, such as operating display screens,driving haptic actuators, etc.

The processing system 110 may be implemented as a set of modules thathandle different functions of the processing system 110. Each module maycomprise circuitry that is a part of the processing system 110,firmware, software, or a combination thereof. In various embodiments,different combinations of modules may be used. Example modules includehardware operation modules for operating hardware such as sensorelectrodes and display screens, data processing modules for processingdata such as sensor signals and positional information, and reportingmodules for reporting information. Further example modules includesensor operation modules configured to operate sensing element(s) todetect input, identification modules configured to identify gesturessuch as mode changing gestures, and mode changing modules for changingoperation modes.

In some embodiments, the processing system 110 responds to user input(or lack of user input) in the sensing region 120 directly by causingone or more actions. Example actions include changing operation modes,as well as GUI actions such as cursor movement, selection, menunavigation, and other functions. In some embodiments, the processingsystem 110 provides information about the input (or lack of input) tosome part of the electronic system (e.g., to a central processing systemof the electronic system that is separate from the processing system110, if such a separate central processing system exists). In someembodiments, some part of the electronic system processes informationreceived from the processing system 110 to act on user input, such as tofacilitate a full range of actions, including mode changing actions andGUI actions.

For example, in some embodiments, the processing system 110 operates thesensing element(s) of the input device 100 to produce electrical signalsindicative of input (or lack of input) in the sensing region 120. Theprocessing system 110 may perform any appropriate amount of processingon the electrical signals in producing the information provided to theelectronic system. For example, the processing system 110 may digitizeanalog electrical signals obtained from the sensor electrodes. Asanother example, the processing system 110 may perform filtering,scaling, or other signal conditioning. As yet another example, theprocessing system 110 may subtract or otherwise account for a baseline,such that the information reflects a difference between the electricalsignals and the baseline. As yet further examples, the processing system110 may determine positional information, recognize inputs as commands,recognize handwriting, and the like.

“Positional information” as used herein broadly encompasses absoluteposition, relative position, velocity, acceleration, and other types ofspatial information. Exemplary “zero-dimensional” positional informationincludes near/far or contact/no contact information. Exemplary“one-dimensional” positional information includes positions along anaxis. Exemplary “two-dimensional” positional information includesmotions in a plane. Exemplary “three-dimensional” positional informationincludes instantaneous or average velocities in space. Further examplesinclude other representations of spatial information. Historical dataregarding one or more types of positional information may also bedetermined and/or stored, including, for example, historical data thattracks position, motion, or instantaneous velocity over time.

In some embodiments, the input device 100 is implemented with additionalinput components that are operated by the processing system 110 or bysome other processing system. These additional input components mayprovide redundant functionality for input in the sensing region 120 orsome other functionality. FIG. 1 shows buttons 130 near the sensingregion 120 that can be used to facilitate selection of items using theinput device 100. Other types of additional input components includesliders, balls, wheels, switches, and the like. Conversely, in someembodiments, the input device 100 may be implemented with no other inputcomponents.

In some embodiments, the input device 100 comprises a touch screeninterface, and the sensing region 120 of the sensing device overlaps atleast part of an active area of a display screen of the display device160. For example, the input device 100 may comprise substantiallytransparent sensor electrodes overlaying the display screen and providea touch screen interface for the associated electronic system. Thedisplay screen may be any type of dynamic display capable of displayinga visual interface to a user, and may include any type of light emittingdiode (LED), organic LED (OLED), cathode ray tube (CRT), liquid crystaldisplay (LCD), plasma, electroluminescence (EL), or other displaytechnology. The input device 100 and the display screen may sharephysical elements. For example, some embodiments may utilize some of thesame electrical components for displaying and sensing. As anotherexample, the display screen may be operated in part or in total by theprocessing system 110.

It should be understood that while many embodiments of the invention aredescribed in the context of a fully functioning apparatus, themechanisms of the present invention are capable of being distributed asa program product (e.g., software) in a variety of forms. For example,the mechanisms of the present invention may be implemented anddistributed as a software program on information bearing media that arereadable by electronic processors (e.g., non-transitorycomputer-readable and/or recordable/writable information bearing mediareadable by the processing system 110). Additionally, the embodiments ofthe present invention apply equally regardless of the particular type ofmedium used to carry out the distribution. Examples of non-transitory,electronically readable media include various discs, memory sticks,memory cards, memory modules, and the like. Electronically readablemedia may be based on flash, optical, magnetic, holographic, or anyother storage technology.

FIG. 2 is a partial schematic plan view of the input device 100 of FIG.1 in accordance with embodiments of the invention. The input device 100includes an array of sensing elements 150, a processing system 110, anda synchronization mechanism 280. The array of sensing elements 150includes a plurality of common electrodes 210 (e.g., 210-1, 210-2,210-3, etc.) and a plurality of receiver electrodes 220 (e.g., 220-1,220-2, 220-3, etc.). The processing system 110 may include two separateprocessing system integrated circuits (ICs) (e.g., processing system IC110-1 and processing system IC 110-2). Processing system IC 110-1, 110-2may include a driver module 240, a receiver module 245, a determinationmodule 250, and/or a memory 260 and a synchronization mechanism 380.

The processing system IC 110-1 is coupled to the plurality of receiverelectrodes 220 and configured to receive resulting signals from thereceiver electrodes 220. Processing system IC 110-1 may also beconfigured to pass the resulting signals to the determination module 250for determining the presence of an input object and/or to the memory 260for storage. In various embodiments, the processing system IC 110-2 maybe coupled to optional drivers 290 for the common electrodes. Theoptional drivers 290 may be fabricated using the thin-film-transistors(TFT) and may comprise switches, combinatorial logic, level shifters,multiplexers, and other selection and control logic to drive selectedcommon electrodes.

The processing system IC 110-2 is coupled to the common electrodes 210through a plurality of conductive routing traces 215-1, 215-2(collectively “215”). Processing system IC 110-2 includes displaycircuitry (not shown) and a driver module 240, one or both of which maybe configured for updating images on the display screen of the displaydevice 160. For example, the display circuitry may be configured toapply one or more pixel voltages to the display pixel electrodes throughpixel source drivers (not shown). The display circuitry may also beconfigured to apply one or more common drive voltages to the commonelectrodes 210 (selected ones of the common electrodes 210) with thedriver module 240 to update the display screen. In addition, theprocessing system IC 110-2 is configured to operate the commonelectrodes 210 as transmitter electrodes for input sensing by drivingtransmitter signals onto the common electrodes 210 (selected ones of thecommon electrodes 210) with the driver module 240.

As shown in FIG. 2, conductive routing traces 215-1 are coupled to oneend of each common electrode 210, and conductive routing traces 215-2are coupled to the other end of each common electrode 210 such that eachcommon electrode 210 is driven for input sensing and/or display updatingfrom both ends. It is also contemplated that conductive routing traces215 may be coupled to only a single end of each of the common electrodes210 or have another configuration.

While the processing system illustrated in FIG. 2 includes twointegrated circuits (ICs), the processing system may be implemented withmore or less ICs to control the various components in the input device.For example, the functions of the processing system IC 110-1 and theprocessing system IC 110-2 may be implemented in one integrated circuitthat can control the display module elements (e.g., common electrodes210) and drive transmitter signals and/or receive resulting signalsreceived from the array of sensing elements 150. In embodiments wherethere are more than one processing system IC, communications betweenseparate processing system ICs 110-1, 110-2 may be achieved through thesynchronization mechanism 280, which sequences the signals provided tothe common electrodes 210. Alternatively the synchronization mechanismmay be internal to a single one of any one of the IC's.

Common electrodes 210 and receiver electrodes 220 are ohmically isolatedfrom each other by one or more insulators which separate the commonelectrodes 210 from the receiver electrodes 220 and prevent them fromelectrically shorting to each other. The electrically insulativematerial separates the common electrodes 210 and the receiver electrodes220 at cross-over areas at which the electrodes intersect. In one suchconfiguration, the common electrodes 210 and/or receiver electrodes 220are formed with jumpers connecting different portions of the sameelectrode. In other configurations, the common electrodes 210 and thereceiver electrodes 220 are separated by one or more layers (e.g.,coupled through vias) of electrically insulative material or by one ormore continuous substrates, as described in further detail below.

The areas of localized capacitive coupling between common electrodes 210and receiver electrodes 220 may be termed “capacitive pixels.” Thecapacitive coupling between the common electrodes 210 and receiverelectrodes 220 changes with the proximity and motion of input objects inthe sensing region 120 associated with the common electrodes 210 and thereceiver electrodes 220.

In various embodiments of the invention, the conductive routing traces215 are shielded from the receiver electrodes 220. In the embodimentdepicted in FIG. 2, the conductive routing traces 215 are shielded fromthe receiver electrodes 220 by shield electrodes 230-1, 230-2(collectively “230”) in a manner that reduces the capacitive couplingbetween the conductive routing traces 215 and the receiver electrodes220. The shield electrodes 230 may be vertically aligned over theconductive routing traces 215 and are positioned between the conductiverouting traces 215 and the receiver electrodes 220. The shieldelectrodes 230 may also be positioned between the conductive routingtraces 215 and an input object to reduce capacitive coupling between theconductive routing traces 215 and the input object, which may affect thecapacitive signals received by the receiver electrodes 220. To preventthe shield electrodes 230 from interfering with the transmission ofsignals to the common electrodes 210, the shield electrodes 230 areelectrically isolated from the conductive routing traces 215, forexample, by an insulating layer 232.

The shield electrodes 230 may suppress the degree to which other sourcesof interference (e.g., signal transmitters, wireless radios, externalinterference coupled through an input object, etc.) affect the qualityof the signal received by the receiver electrodes 220. For example, whenpositioned between the conductive routing traces 215 and the receiverelectrodes 220 and/or between the conductive routing traces 215 and aninput object (e.g., a finger, a stylus, etc.), the shield electrodes 230reduce the effect of the input object on the capacitive coupling betweenthe conductive routing traces 215 and the receiver electrodes 220. As aresult, because various capacitance sensing methods are based ondetecting changes in capacitive coupling (e.g., mutual capacitancemethods), “noise” produced due to the capacitive coupling of theconductive routing traces 215 with the input object and/or receiverelectrodes 220 is reduced, increasing the accuracy with which thepresence or absence of the input object can be detected. Reducing noisefrom the conductive routing traces 215 is particularly important nearthe edges of the sensing region 120, where there are fewer capacitive“pixels” and, consequently, less input sensing information. Thus, theshield electrodes 230 increase response uniformity between the centerand edges of the sensing region 120, increasing the accuracy with whichthe sensing region 120 is able to detect the presence or absence of aninput object. In one embodiment, the shield electrodes 230 increaseresponse uniformity between the center and edges of the sensing region120, increasing the accuracy with which the sensing region 120 is ableto detect the presence or absence of an input object especially near anedge of the input device 100.

The shield electrodes 230 are made of a conducting material, such as ametal or a transparent conductive oxide (e.g., indium tin oxide), andmay be formed as solid strip, a mesh, or any other configuration whichis capable of blocking electromagnetic fields. In addition, although theshield electrodes 230 are shown as rectangular in shape, they may beformed in any shape which effectively shields the receiver electrodes220 from the conductive routing traces 215. In some embodiments, theshield electrodes 230 may be disposed around the edges of the deviceand/or may also serve as an electrostatic discharge (ESD) strike ring.

The shield electrodes 230 may be driven with a shield signal, such as asystem ground of the device. In other embodiments, the shield electrodes230 are driven with a constant voltage signal or with any other signalable to sufficiently shield the conductive routing traces 215. Theshield electrode(s) 230 may be coupled with one or more processingsystem ICs 110, and one or more processing system ICs 110 may beconfigured to drive the shield electrode(s) 230. For example, one ormore shield electrodes 230 may be coupled to one or more processingsystem ICs 110 through a common flexible connector, flexible printedcircuit (FPC), such as a “flex tail,” or other connecting device.Optionally, the flex tail may include a shield electrode and may becoupled to the receiver electrodes 220 by a plurality ofthrough-connections, contacts or vias 295 disposed on a sealing glasslayer of the input device 100. In another embodiment, a flex tail,distinct from the flex tail coupled to the receiver electrodes 220 maybe coupled to the display device.

Although various embodiments presented herein describe the shieldelectrodes 230 as being positioned between the receiver electrodes 220and the conductive routing traces 215 to reduce capacitive couplingbetween these elements, the shield electrodes 230 may also be positionedsuch that they do not directly obstruct the line-of-sight between theseelements. That is, configurations in which the shield electrodes 230 arepositioned off-axis from the line-of-sight between the receiverelectrodes 220 and the conductive routing traces 215 may providesufficient shielding to reduce the capacitive coupling between thereceiver electrodes 220 and the conductive routing traces 215.Consequently, the shield electrodes 230 may be disposed on the samelayer as the receiver electrodes 220, or the shield electrodes 230 maybe disposed on a layer that is between the lens (510 in FIG. 5) and thelayer on which the receiver electrodes 220 are disposed. In oneembodiment, an optional flexible printed circuit may be coupled to theinput device, where the optional flexible printed circuit comprises ashield electrode that is separate from shield electrode 230. In yetanother embodiment, shield electrode 230 may be integrated within adisplay device.

FIG. 3 is a partial schematic plan view of the input device 100 having atwo-shield configuration. FIG. 4 is a partial schematic plan view of theinput device 100 having a single-shield configuration. In the two-shieldconfiguration, conductive routing traces 215-1 are shielded by shieldelectrode 230-1, and conductive routing traces 215-2 are shielded byshield electrode 230-2. In this configuration, the shield electrodes230-1, 230-2 may be coupled together with one or more conductive routingtraces 215, for example, in order to provide a shield signal to theshield electrodes 230. In the single-shield configuration, both sets ofconductive routing traces 215-1, 215-2 are shielded by shield electrode230. Other shield configurations, such as configurations including threeor more shield electrodes, may also be used with the input and displaydevices 100, 160 described herein.

In order to prevent the shield electrode(s) 230 from acting as anantenna—and potentially interfering with wireless communication signalssent to and from the device in which input device 100 is disposed—theshield electrode(s) 230 may be configured such that they do not form aclosed loop. Thus, in the two-shield configuration shown in FIG. 3,shield electrode 230-1 is electrically isolated from shield electrode230-2. In the single-shield configuration shown in FIG. 4, the shieldelectrode 230 may be connected to the flex cable at a single end and,thus, does not form a closed loop. In one embodiment, the shieldelectrode 230 may be connected to a separate shield on the flex cable ata single end.

FIG. 5 is an exploded schematic view of a liquid crystal display (LCD)device 500 integrated with input device 100. The LCD device 500 includesinput device 100, a lens 510, polarizing layers 520-1, 520-2, a sealinglayer 530 (e.g., a color filter glass layer), a liquid crystal layer540, and a thin-film transistor (TFT) substrate layer 545. The commonelectrodes 210 and conductive routing traces 215 of the input device 100are disposed on a bottom surface (i.e., a surface facing away from theuser) of the sealing layer 530 (e.g., a vertical alignment LCD). Thereceiver electrodes 220 of the input device 100 are disposed on a topsurface (i.e., a surface facing towards the user) of the sealing layer530. The shield electrodes 230 are disposed on the bottom surface of thesealing layer 530 between the conductive routing traces 215 and the lens510.

Although FIG. 5 shows the receiver electrodes 220 as being disposed onthe top surface of the sealing layer 530, it is contemplated that thereceiver electrodes 220 may be disposed on any layer of the device(e.g., top or bottom surfaces of polarizing layer 520-1, bottom surfaceof the lens, etc.), so long as the receiver electrodes 220 areelectrically isolated from the common electrodes 210 and are positionedbetween the lens 510 and the common electrodes 210. In one embodiment,the sensor electrodes (the common electrodes and the receivingelectrodes) may be disposed on the same layer.

The LCD device 500 may be a vertically aligned LCD device (e.g., apatterned vertical alignment LCD, multi-domain vertical alignment LCD,etc.). Consequently, in the configuration shown in FIG. 5, the commonelectrodes 210, which are configured to be driven for input sensing anddisplay updating, are disposed proximate the top surface of the liquidcrystal layer 540. However, in other display types (e.g., in-planeswitching (IPS), plane-to-line switching (PLS), twisted nematic (TN),etc.), the common electrodes 210 may be disposed on any layer whichenables the electrodes to be driven for both input sensing and displayupdating.

FIG. 6 is an exploded schematic view of a LCD device 600 integrated withinput device 100. The LCD device 600 may be an IPS- or PLS-type LCDdevice. Thus, the common electrodes 210 are disposed on the top surfaceof the TFT substrate layer 545. The shield electrodes 230 are disposedon the top surface of the TFT substrate layer 545, between theconductive routing traces 215 and the lens 510, and/or proximate thebottom surface of the liquid crystal layer 540.

FIG. 7 is an exploded schematic view of a LCD device (e.g., LCD device500 or LCD device 600) illustrating alternative locations at which theshield electrode(s) 230 may be disposed. The shield electrode(s) 230 mayinclude an insulating layer, such as the insulating layer 232 shown inFIG. 2, proximate the top and/or bottom of the shield electrode(s) 230if required to isolate the shield electrode(s) 230 from anotherconductor. In each configuration illustrated in FIG. 7, the shieldelectrode(s) 230 may be disposed on or in one or both of the layers orsubstrates between which they are displayed. For example, the shieldelectrode(s) 230 may be disposed next to the bottom surface of the lens510 and/or on the top surface of the polarizing layer 520-1.Alternatively, the shield electrode(s) 230 may be disposed proximate thebottom of the liquid crystal layer 540 and/or on the top surface of theTFT substrate layer 545. Optionally, the shield electrode(s) 230 may bedisposed within any of the layers and/or substrates illustrated in FIG.7 between the lens 510 and liquid crystal layer 540 in order to shieldthe receiver electrodes 220 from the conductive routing traces 215.

FIG. 8 is an exploded schematic view of an organic light-emitting diode(OLED) display device 800 integrated with input device 100. The OLEDdisplay device 800 includes input device 100, a lens 510, a sealinglayer 530, an OLED layer 810, and a substrate layer 820. The commonelectrodes 210 and conductive routing traces 215 of the input device 100are disposed on the bottom surface of the sealing layer 530. Thereceiver electrodes 220 of the input device 100 are disposed on the topsurface of the sealing layer 530. The shield electrodes 230 are disposedon the bottom surface of the sealing layer 530 between the conductiverouting traces 215 and the lens 510.

FIG. 9 is an exploded schematic view of an OLED display device 800illustrating alternative locations at which the shield electrode(s) 230may be disposed. As discussed above with respect to FIG. 7, in eachconfiguration illustrated in FIG. 9, the shield electrode(s) 230 may bedisposed on or in one or both of the layers or substrates between whichthey are displayed. For example, the shield electrode(s) 230 may bedisposed on the bottom surface of the lens 510 and/or on the top surfaceof the sealing layer 530. Optionally, the shield electrode(s) 230 may bedisposed within any of the layers and/or substrates illustrated in FIG.9 between the lens 510 and liquid crystal layer 540 in order to shieldthe receiver electrodes 220 from the conductive routing traces 215.

In other embodiments of the invention, the end portions of the commonelectrodes 210 may be configured as shield electrodes as to shield thereceiver electrodes 220 from the conductive routing traces 215 to reducethe capacitive coupling between the receiver electrodes 220 and theconductive routing traces 215. For example, as shown in FIG. 10, thereceiver electrodes 220 are shielded from the conductive routing traces215 by end portions 1030 of the common electrodes 210 such that the endportions 1030 of the common electrodes 210 reduce the effect that aninput object has on the capacitive coupling between the receiverelectrodes 220 and the conductive routing traces 215. This“self-shielding” configuration enables the common electrodes 210 to beextended further towards the edges 1020 of the display device 160 and,consequently, enables display image pixels to be located closer to theedges of the display device 160, reducing the thickness of the borderaround the screen of the display device 160.

FIGS. 11A and 11B are schematic cross-sectional views of the input anddisplay device 100, 160 of FIG. 10 in accordance with differentembodiments of the invention. As shown in FIGS. 11A and 11B, theconductive routing traces 215 are routed below the end portions 1030 ofthe common electrodes 210 and are electrically isolated from the commonelectrodes 210 by an insulating layer 1110. Each conductive routingtrace 215 is coupled to a bottom surface of a common electrode 210 by athrough-connection 1010 disposed in a via formed in the insulating layer1110. As both the through-connection 1010-1 and conductive routingtraces 215-1 are below the common electrode 210, with the commonelectrode 210 blocking the line of sight path between the traces 215-1and receiver electrodes 220, the common electrodes 210 effectivelyshield the conductive routing traces 215-1 from the receiver electrodes220, thereby reducing the capacitive coupling between the conductiverouting traces 215-1 and the receiver electrodes 220.

In FIG. 11A, the through-connection 1010-1 and the conductive routingtrace 215-1 each are disposed in the insulating layer 1110. Thesubstrate 1120 shown in FIG. 11A may be any substrate or layer (e.g.,glass, plastic, or the like) of the display device 160, such as a liquidcrystal layer, an OLED layer, etc. In FIG. 11B, the conductive routingtrace 215-1 a is disposed in an insulating layer 1110 that is positionedbetween the liquid crystal layer 540 and the TFT substrate layer 545 ofthe display device 160 (e.g., on a sealing ring of the display device).In this configuration, one of the conductive routing traces 215-1 a isconnected to the common electrode 210-1 by a through-connection 1010-1disposed proximate the liquid crystal layer 540. As shown in FIG. 11B,the through-connection 1010-1 may be insulated from the liquid crystallayer 540 by an insulating or sealing ring disposed around thethrough-connection 1010-1.

FIG. 12 is a schematic plan view of the input and display device 100,160 of FIG. 10 in which apertures 1210 are formed in the commonelectrodes 210 to decrease coupling between the conductive routingtraces 215 and the common electrodes 210 from which they are designed tobe electrically isolated. For example, aperture 1210-1 is formed incommon electrode 210-2 to decrease the capacitive coupling betweencommon electrode 210-2 and one of the conductive routing traces 215-1.Although the capacitive coupling between the conductive routing traces215-1 and the common electrode 210-2 is reduced, the end portion of thecommon electrode 210-2 continues to effectively shield the conductiverouting trace 215-1 from the receiver electrodes 220.

FIGS. 13A and 13B are schematic cross-sectional views of the input anddisplay device 100, 160 of FIG. 12 in accordance with differentembodiments of the invention. As shown in FIGS. 13A and 13B, theconductive routing traces 215-1, 215-1 b are electrically isolated fromthe common electrodes 210 by an insulating layer 1110. Each conductiverouting trace 215 is coupled to a bottom of a common electrode 210 by athrough-connection 1010. The common electrode 210 blocks the line ofsight path between the conductive routing traces 215 and the receiverelectrodes 220, thereby shielding the conductive routing traces 215 fromthe receiver electrodes 220. In FIGS. 13A and 13B, an aperture 1210-1 isformed in common electrode 210-2 over the conductive routing trace 215-1a to reduce the capacitive coupling between the conductive routing trace215-1 a and the common electrode 210-2. Optionally, the aperture 1210-1may be filled with an insulating material, as shown in FIGS. 13A and13B.

In FIG. 13A, the conductive routing traces 215-1 and thethrough-connection 1010-2 each are disposed in the insulating layer1110. The substrate 1120 may be any substrate or layer of the displaydevice 160, such as a liquid crystal layer, an OLED layer, etc. In FIG.13B, the conductive routing traces 215-1 are disposed in an insulatinglayer 1110 that is positioned between the liquid crystal layer 540 andthe TFT substrate layer 545 of the display device 160. In thisconfiguration, one of the conductive routing traces 215-1 is connectedto the common electrode 210-2 by a through connection 1010-2 that isdisposed in the liquid crystal layer 540. As shown in FIG. 13B, thethrough-connection 1010-2 may be insulated from the liquid crystal layer540 by an insulating ring or sealing ring disposed around thethrough-connection 1010-2.

Thus, the embodiments and examples set forth herein were presented inorder to best explain the present invention and its particularapplication and to thereby enable those skilled in the art to make anduse the invention. However, those skilled in the art will recognize thatthe foregoing description and examples have been presented for thepurposes of illustration and example only. The description as set forthis not intended to be exhaustive or to limit the invention to theprecise form disclosed.

The invention claimed is:
 1. A touch screen device with an integratedcapacitive sensing device comprising: a display device; a plurality ofcommon electrodes disposed in the display device and configured forupdating the display device and for transmitting transmitter signals forcapacitive sensing; a plurality of receiver electrodes; and a pluralityof conductive routing traces coupled to the plurality of commonelectrodes, the conductive routing traces shielded from the plurality ofreceiver electrodes by end portions of the plurality of commonelectrodes in a manner that reduces a capacitive coupling between theconductive routing traces and the receiver electrodes.
 2. The touchscreen device of claim 1, wherein the plurality of conductive routingtraces are configured for driving the plurality of common electrodes. 3.The touch screen device of claim 1, wherein the plurality of commonelectrodes and the plurality of conductive routing traces and disposedon a thin-film transistor (TFT) substrate layer of the display device,and the plurality of receiver electrodes is disposed below a lens of thedisplay device.
 4. The touch screen device of claim 1, wherein theplurality of common electrodes is configured to reduce the effect of aninput object on the capacitive coupling between the conductive routingtraces and the receiver electrodes.
 5. The touch screen device of claim1, wherein the end portions of the plurality of common electrodes aredisposed between the plurality of receiver electrodes and the pluralityof conductive routing traces, and each of the end portions of theplurality of common electrodes is coupled with a respective one of theplurality of conductive routing traces through a via.
 6. The touchscreen device of claim 1, wherein the plurality of common electrodesfurther comprises apertures formed therethrough and disposed over theplurality of conductive routing traces.
 7. The touch screen device ofclaim 6, wherein the apertures are configured to decrease the capacitivecoupling between the plurality of common electrodes and the plurality ofconductive routing traces.
 8. A system for capacitive sensing in adisplay device comprising: a plurality of common electrodes configuredfor display updating and for capacitive sensing; a plurality ofconductive routing traces coupled to the plurality of common electrodes;a driver module coupled to the plurality of conductive routing tracesand configured to drive transmitter signals onto the plurality of commonelectrodes; a plurality of receiver electrodes shielded from theplurality of conductive routing traces by end portions of the pluralityof common electrodes in a manner that reduces influence of a presence ofan input object on capacitive coupling between the plurality of receiverelectrodes and conductive routing traces; and a receiver module coupledto the plurality of receiver electrodes and configured to receiveresulting signals with the receiver electrodes.
 9. The system of claim8, wherein the end portions of the plurality of common electrodes arepositioned between the plurality of receiver electrodes and theplurality of conductive routing traces.
 10. The system of claim 9,wherein each of the end portions of the plurality of common electrodesare coupled with a respective one of the plurality of conductive routingtraces through a via.
 11. The touch screen device of claim 1, furthercomprising an aperture formed in the end portions of the plurality ofcommon electrodes.
 12. The touch screen device of claim 11, furthercomprising an insulating material disposed in the apertures.